Electrical Which wire to splice gauges to on headlamp switch

1989LXFOX · Apr 7, 2018

Hello all,
I have three gauges going in and I would like to know which wire on the headlamp switch to splice all three to so that the gauges illuminate when I turn on headlights or just instrumentation lights. Is it the light blue/red, tan/white, or brown? I would also like to run the wires to the dimmer to dim the gauges but not sure how to do that. Lastly, can I splice all three feeds from gauges to the same wire?

Mustang5L5 · Apr 7, 2018

Iirc, light blue with red tracer is switch illumination and works off the dimmer so the dimmer would control anything you tap on it

I can confirm later after checking my wiring diagrams

1989LXFOX · Apr 7, 2018

Mustang5L5 said:
Iirc, light blue with red tracer is switch illumination and works off the dimmer so the dimmer would control anything you tap on it

I can confirm later after checking my wiring diagrams

Thanks! So I only have to splice in the wire for the dimmer? That will provide illumination and dimming? Or do I still need to hook up the white wire (12v switched)?

Mustang5L5 · Apr 7, 2018

1989LXFOX said:
Thanks! So I only have to splice in the wire for the dimmer? That will provide illumination and dimming? Or do I still need to hook up the white wire (12v switched)?

Aftermarket gusge wiring is typically white and black wire. Black is usually considered ground.

Ground your black wire somewhere and hook white up to any light blue with red tracer wire. It's tied after the dimmer so the dimmer control will also control brightness of the gusge you install.

Wire circuit 19 above

1989LXFOX · Apr 7, 2018

Mustang5L5 said:
Aftermarket gusge wiring is typically white and black wire. Black is usually considered ground.

Ground your black wire somewhere and hook white up to any light blue with red tracer wire. It's tied after the dimmer so the dimmer control will also control brightness of the gusge you install.

Wire circuit 19 above

For you to take the time out of your day/night I greatly appreciate my brother! Thank you!

1989LXFOX · Apr 13, 2018

Mustang5L5 said:
Aftermarket gusge wiring is typically white and black wire. Black is usually considered ground.

Ground your black wire somewhere and hook white up to any light blue with red tracer wire. It's tied after the dimmer so the dimmer control will also control brightness of the gusge you install.

Wire circuit 19 above

Sooooo please keep in mind I am total noob! I think I messed up. My gauges have 4 wires each (glowshift). A black ground, red power (12v switched), orange (12v switched head lamp - OPTIONAL) and a yellow wire (12v unswitched constant source) and a green wire (signal).
I, wrongly, went ahead and spliced the orange wires ONLY to the red blue wire in the picture. Did not use the yellow and hooked my red ground up.
When I turn on ignition the gauges get power but no backlighting. I assume I screwed up with not using yellow wire, which I did, BUT I hooked up the white wire from an aftermarket tach to the red/blue also and it gives me illumination on the tach but the dimming proceess is reversed (when I bring the wheel all the way to the right the instrument panel illumination gets bright and tach turns off and vice versa.
At this point I don’t care about th dimming feature, I just need to figure what wire to connect the yellow to so that the gauges illuminate when I turn on my headlamp switch.

Sorry for the lengthy post!

Mustang5L5 · Apr 13, 2018

Tan with white tracer wire is hot at all times. Circuit 195 in the wiring diagram above.

1989LXFOX · Apr 13, 2018

So splice the yellow wire (12v unswitched constant source) onto the Tan/White tracer? Should I pull the orange off the light blue/red tracer? Thanks again

Mustang5L5 · Apr 13, 2018

If oranges is illumination on the gusge you can leave it

mikestang63 · Apr 15, 2018

look. make this simple
for the illumination on your gauges just splice them all into one wire into the illumination wire off the radio.
When you turn the lights its the wire that lights up the radio
For the constant power use an add a circuit fuse kit and plug that into your radio fuse as well. The radio is always on.
The ground goes to a good chassis ground. You can find them all over the place
The last wire if the gauges are electric are to the sending unit
You can download the instructions off Autometer site.
I would solder all the wire connections together and use heat shrink
IF you cant solder at least use good crimp connectors with heat shrink

General karthief · Apr 16, 2018

Crimp connectors are ugly, learn to solder, it's easy, I take the plastic off the crimp connectors and use just the metal part when glueing wires together, one of the guys at the shop built this nifty wire holder from a magnet and a pair of alligator clips, just remember to slip the heat shrink tube on BEFORE you start glueing wires together!

Electrical Which wire to splice gauges to on headlamp switch

1989LXFOX

Active Member

Mustang5L5

That is…until I whipped out my Bissell

1989LXFOX

Active Member

Mustang5L5

That is…until I whipped out my Bissell

1989LXFOX

Active Member

1989LXFOX

Active Member

Mustang5L5

That is…until I whipped out my Bissell

1989LXFOX

Active Member

Mustang5L5

That is…until I whipped out my Bissell

mikestang63

General karthief

wonder how much it would cost to ship you a pair

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Electrical Which wire to splice gauges to on headlamp switch

Active Member

That is…until I whipped out my Bissell

Active Member

That is…until I whipped out my Bissell

Active Member

Active Member

That is…until I whipped out my Bissell

Active Member

That is…until I whipped out my Bissell

wonder how much it would cost to ship you a pair

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